A device and method for handling downhole accidents in oil and gas wells

Abstract

The invention discloses an oil and gas well downhole accident handling device and method, comprising a body, a driving piston, a reset spring, a supporting ring plate, a torsion spring, a ratchet, a pin shaft, a slip claw and a guide head; the method is that when the device is lowered into the well with the drill string during salvage operation, the circulating drilling fluid causes the driving piston to move downward and compress the spring, the drilling fluid enters the body through the drainage hole on the body and is discharged from the drilling fluid flow channel of the guide head; during the process, the driving piston drives the slip claw to move downward, the claw block slides on the guide head reducing section and increases the outer diameter so as to bite the fish, and the fish can be taken out by lifting the pipe column; the ratchet acts with the limit ratchet during the movement of the slip claw to prevent the slip claw from moving upward under the action of the reset spring; when the fish is stuck too tightly and cannot be taken out, the pipe column is rotated to make the ratchet slide into the pin release groove, the piston is driven to move upward under the action of the reset spring, the slip claw releases the fish, and the pipe column is lifted out at this time. The device is short in length and has no electronic components, and is easy to operate.

Description

Technical Field

[0001] The invention relates to a downhole tool, in particular to a downhole accident handling device and method for an oil and gas well, belonging to the technical field of mechanical engineering or drilling engineering. Background Art

[0002] Oil and gas production plays a vital role in the country's economic development and is even related to national security. In recent years, under the background of rapid economic development, my country has vigorously developed the exploration and development of oil and gas resources. However, after years of exploitation, shallow oil and gas resources have gradually decreased, and deep complex oil and gas and unconventional oil and gas have gradually become the focus of exploitation. As the well depth increases and the wellbore trajectory becomes more complex, the possibility of accidents in downhole equipment increases. When downhole accidents such as the breakage of downhole tools such as drill strings, casing strings or tubing strings occur, special accident handling devices are usually used for salvage operations.

[0003] The more mature existing salvage devices include salvage tubes and male cones. These tools have simple structures and fixed sizes. They cannot change diameters during salvage and are prone to not biting the fish tightly. In recent years, in response to frequent drilling and completion accidents, a variety of retractable salvage tools have emerged. However, with the increase in deep wells and complex wells such as directional wells, large displacement wells, and horizontal wells, the application of existing salvage tools is subject to many restrictions. In order to enrich the structure of the accident handling device, it is necessary to design a new accident handling device with a variable diameter and retractable structure. Summary of the invention

[0004] The purpose of the present invention is to provide an underground accident handling device and method for oil and gas wells, which is used to fish out fish from the well when a drilling accident occurs, thereby enabling the continuous development of drilling and production operations.

[0005] The technical solution adopted by the present invention is:

[0006] A downhole accident handling device for oil and gas wells comprises a body, a driving piston, a return spring, a supporting ring plate, a torsion spring, a pawl, a pin shaft, a slip claw and a guide head, the body is provided with a body outer cylinder, a body inner cylinder and a body connecting plate, the upper end of the body outer cylinder is provided with an outer cylinder female buckle, the body inner cylinder is provided with two axial splines evenly distributed in the circumferential direction, a dredging hole, a limit ratchet, an unlocking groove and an inner cylinder male buckle, the body connecting plate is provided with a drilling fluid circulation hole, the limit ratchet is provided with a ratchet plane and a non-return step; the driving piston comprises a piston large diameter section and a piston small diameter section, the inner wall of the driving piston is provided with two spline grooves evenly distributed in the circumferential direction, and the lower end of the piston small diameter section is provided with a piston male buckle; the torsion spring comprises a torsion spring fixing section and a torsion spring loading section; the pawl comprises a pawl rotating hole, a pawl back side and a pawl tip; the slip claw comprises a claw block, an inter-block longitudinal groove, a torsion spring placement groove, a pin shaft mounting hole and a slip claw female buckle, The outer wall of the claw block is provided with a slip tooth, and the claw block and the longitudinal grooves between the blocks are staggered and evenly distributed circumferentially, the slip claw female buckle is arranged at the upper end of the inner wall of the slip claw, and the inner wall of the torsion spring placement groove is provided with two torsion spring limiting grooves; the guide head comprises a guide head reducing section, a guide head straight section, a drilling fluid channel and a guide head female buckle; the driving piston is sleeved in the annular space formed by the outer cylinder of the body and the inner cylinder of the body, the axial spline cooperates with the spline groove, and the support ring plate is connected to the lower end of the outer cylinder of the body by a thread; a reset spring is provided between the lower end surface of the large diameter section of the piston and the support ring plate; the piston male buckle of the driving piston cooperates with the slip claw female buckle of the slip claw; the inner cylinder male buckle cooperates with the guide head female buckle; the torsion spring is installed in the torsion spring placement groove, and the two ends of the torsion spring fixing section are arranged in the torsion spring limiting groove, the torsion spring loading section applies pressure to the back of the pawl, the pin shaft passes through the torsion spring, the pawl rotation hole and the pin shaft mounting hole, and the pawl can rotate around the pin shaft.

[0007] Furthermore, the upper end of the oil and gas well downhole accident handling device is connected to the drill string, and the drilling fluid can flow to the drainage hole through the drilling fluid circulation hole on the main body connecting plate, and finally flow out from the drilling fluid flow channel on the guide head.

[0008] A plug is threadedly connected in the pin shaft mounting hole.

[0009] Furthermore, the plug is used to prevent the pin from falling off from the pin mounting hole.

[0010] Sealing rings are arranged between the large diameter section of the piston and the inner wall of the outer cylinder of the body, and between the supporting ring plate and the outer wall of the upper end of the slip claw.

[0011] Furthermore, there is no liquid in the annular space formed by the lower end surface of the large diameter section of the piston, the upper end surface of the support ring plate, the inner wall of the main body outer cylinder, and the outer wall of the main body inner cylinder.

[0012] The outer diameter of the large end of the guide head reducing section is equal to the outer diameter of the guide head straight section.

[0013] Furthermore, when the claw block moves from the small diameter of the guide head reducing section to the large diameter of the guide head reducing section, the outer diameter of the claw block increases, so as to be used to bite the fallen fish.

[0014] The ratchet plane and the unlocking groove on the limiting ratchet are 180 degrees apart in the circumferential direction.

[0015] Furthermore, when the fish is salvaged normally, the pawl interacts with the ratchet tooth plane; when the jam needs to be released, the pawl interacts with the unlocking groove.

[0016] The method of the downhole accident handling device of an oil and gas well is as follows: when a downhole accident occurs and a fish needs to be salvaged, the downhole accident handling device of the oil and gas well is connected to the lowermost end of the drill string through the outer tube female buckle and lowered into the well. When the fish is reached, the drilling fluid is circulated, and the drilling fluid enters the annular cavity formed by the lower end face of the body connecting plate, the upper end face of the large diameter section of the piston, the inner wall of the body outer tube and the outer wall of the body inner tube from the drilling fluid circulation hole on the body connecting plate. The drilling fluid drives the driving piston to move downward and compresses the reset spring until it is above the large diameter section of the piston. The drilling fluid in the annular cavity can flow into the inner tube of the body through the drainage hole, and the drilling fluid finally enters the outer annulus between the drill string and the well wall through the drilling fluid flow channel; since the driving piston and the slip claw are fixedly connected by threads, the driving piston drives the slip claw to move downward during the downward movement; in the initial state, the inner diameter of the claw block on the slip claw is larger than the outer diameter of the small end of the guide head reducing section and the outer diameter of the claw block is smaller than the outer diameter of the guide head straight tube section, and the outer diameter of the guide head straight tube section is smaller than the inner diameter of the fish drop; when the slip claw moves downward, the lower end of the claw block slides along the guide head reducing section so that the outer diameter of the claw block As the diameter increases, the slip teeth bite the inner wall of the fish and lift the pipe string. Under the friction between the slip teeth and the inner wall of the fish, the slip claws tend to continue to slide downward relative to the guide head and make the slip claws bite the inner wall of the fish more and more tightly. The fish can be salvaged as the drill string is lifted up. In this process, the ratchet claw moves downward with the slip claw. The engagement between the axial spline and the spline groove is released when the driving piston moves downward to the limit position. Under the action of the torsion spring, the tip of the ratchet claw is always in contact with the outer surface of the inner cylinder of the body. The tip of the ratchet claw slides downward along the ratchet plane and is restrained by the anti-return platform. The tip of the step-limiting pawl can only slide downward but not upward; when the fish is stuck too tightly and cannot be extracted from the drill string, the handling device that bites the fish needs to be taken out. At this time, the drill string is rotated 180 degrees. The body rotates but the cava claw bites the fish and cannot rotate. The pawl slides in the annular groove of the limiting ratchet until it reaches the unlocking groove. The drill string is vibrated slightly. Under the action of the reset spring, the piston is driven to move upward and the pawl is driven to slide along the unlocking groove. The outer diameter of the claw block is reduced and the fish is released. The drill string can be lifted up to lift the downhole accident handling device.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The structure of the present invention is simple and practical. During salvage, the device and the fallen fish are locked together by the cooperation between the pawl and the limit ratchet, and the action between the device and the fallen fish is reliable; (2) When the fallen fish cannot be salvaged, the drill string can be rotated on the ground to make the pawl slide into the unlocking groove and unlock, thus avoiding the situation where the drill string cannot be lifted out; (2) The device has no electronic components, the tool length is short, and it can be applied to high temperature and high pressure environments and wells with large doglegs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural schematic diagram of an oil and gas well downhole accident handling device of the present invention;

[0019] Figure 2 for Figure 1 A magnified view of part I;

[0020] Figure 3 This is a structural schematic diagram of a main body of an oil and gas well downhole accident handling device of the present invention;

[0021] Figure 4 for Figure 3 A magnified view of part I;

[0022] Figure 5 Another structural schematic diagram of the main body of an oil and gas well downhole accident handling device of the present invention;

[0023] Figure 6 Another structural schematic diagram of the main body of an oil and gas well downhole accident handling device of the present invention;

[0024] Figure 7 This is a schematic diagram of the structure of a driving piston in a downhole accident handling device for an oil and gas well according to the present invention;

[0025] Figure 8 It is a structural schematic diagram of a torsion spring in a downhole accident handling device for an oil and gas well according to the present invention;

[0026] Fig. 9 Another structural schematic diagram of a torsion spring in an oil and gas well downhole accident handling device according to the present invention;

[0027] Fig.10 It is a structural schematic diagram of a ratchet in a downhole accident handling device for an oil and gas well according to the present invention;

[0028] Fig.11 It is a structural schematic diagram of a slip claw in a downhole accident handling device for oil and gas wells of the present invention;

[0029] Fig.12 Another structural schematic diagram of a slip claw in a downhole accident handling device for oil and gas wells according to the present invention;

[0030] Fig.13 It is a structural schematic diagram of a guide head in a downhole accident handling device for oil and gas wells of the present invention;

[0031] Fig.14 This is a schematic diagram of the overall structure of an oil and gas well downhole accident handling device of the present invention;

[0032] Fig.15 for Fig.14 A magnified view of part I;

[0033] Fig.16 Another overall structural schematic diagram of an oil and gas well downhole accident handling device of the present invention;

[0034] Fig.17 for Fig.16 A magnified view of part I;

[0035] In the figure: 1-body, 1a-body outer cylinder, 1b-body inner cylinder, 1c-body connecting plate, 1d-axial spline, 1e-drainage hole, 1f-limit ratchet, 1g-ratchet plane, 1h-unlocking groove, 1i-drilling fluid circulation hole, 1j-outer cylinder female buckle, 1k-inner cylinder male buckle, 1m-check step, 2-driving piston, 2a-piston large diameter section, 2b-piston small diameter section, 2c-spline groove, 2d-piston male buckle, 3-reset spring, 4-support ring plate, 5-torsion spring, 5a -torsion spring fixing section, 5b-torsion spring loading section, 6-pawl, 6a-pawl rotation hole, 6b-pawl back, 6c-pawl tip, 7-pin shaft, 8-claw claw, 8a-claw block, 8b-claw tooth, 8c-longitudinal groove between blocks, 8d-torsion spring placement groove, 8e-pin shaft mounting hole, 8f-claw claw female buckle, 8g-torsion spring limiting groove, 9-guide head, 9a-guide head reducing section, 9b-guide head straight section, 9c-drilling fluid flow channel, 9d-guide head female buckle, 10-plug, 11-sealing ring. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] Example:

[0038] like Figure 1-17As shown, an oil and gas well downhole accident handling device comprises a body 1, a driving piston 2, a return spring 3, a support ring plate 4, a torsion spring 5, a ratchet 6, a pin 7, a slip claw 8 and a guide head 9, the body 1 is provided with a body outer cylinder 1a, a body inner cylinder 1b and a body connecting plate 1c, the upper end of the body outer cylinder 1a is provided with an outer cylinder female buckle 1j, the body inner cylinder 1b is provided with two axial splines 1d evenly distributed along the circumferential direction, a drainage hole 1e, a limit ratchet 1f, an unlocking groove 1h and an inner cylinder male buckle 1k, and the body connecting plate 1c is provided with a drilling fluid circulation hole 1i , the limit ratchet 1f is provided with a ratchet plane 1g and a check step 1m; the driving piston 2 includes a piston large diameter section 2a and a piston small diameter section 2b, the inner wall of the driving piston 2 is provided with two spline grooves 2c evenly distributed along the circumferential direction, and the lower end of the piston small diameter section 2b is provided with a piston male buckle 2d; the torsion spring 5 includes a torsion spring fixing section 5a and a torsion spring loading section 5b; the pawl 6 includes a pawl rotating hole 6a, a pawl back 6b and a pawl tip 6c; the slip claw 8 includes a claw block 8a, an inter-block longitudinal groove 8c, a torsion spring placement groove 8d, a pin shaft mounting hole 8e and a slip claw The outer wall of the claw block 8a is provided with a slip tooth 8b, the claw block 8a and the inter-block longitudinal groove 8c are staggered and evenly distributed circumferentially, the slip claw female buckle 8f is arranged at the upper end of the inner wall of the slip claw 8, and the inner wall of the torsion spring placement groove 8d is provided with two torsion spring limit grooves 8g; the guide head 9 includes a guide head reducing section 9a, a guide head straight section 9b, a drilling fluid channel 9c and a guide head female buckle 9d; the driving piston 2 is sleeved in the annular space formed by the outer cylinder 1a of the body and the inner cylinder 1b of the body, the axial spline 1d cooperates with the spline groove 2c, and the support ring plate 4 is through It is threadedly connected to the lower end of the outer cylinder 1a of the main body; a reset spring 3 is provided between the lower end surface of the large-diameter section 2a of the piston and the supporting ring plate 4; the piston male buckle 2d of the driving piston 2 cooperates with the cava claw female buckle 8f of the cava claw 8; the inner cylinder male buckle 1k cooperates with the guide head female buckle 9d; the torsion spring 5 is installed in the torsion spring placement groove 8d, and the two ends of the torsion spring fixing section 5a are arranged in the torsion spring limiting groove 8g, the torsion spring loading section 5b applies pressure to the back side 6b of the pawl, and the pin shaft 7 passes through the torsion spring 5, the pawl rotation hole 6a and the pin shaft mounting hole 8e, and the pawl 6 can rotate around the pin shaft 7.

[0039] A plug 10 is threadedly connected in the pin shaft mounting hole 8e.

[0040] Sealing rings 11 are provided between the large diameter section 2a of the piston and the inner wall of the outer cylinder 1a of the main body, and between the supporting ring plate 4 and the outer wall of the upper end of the slip claw 8.

[0041] The outer diameter of the large end of the guide head reducing section 9a is equal to the outer diameter of the guide head straight section 9b.

[0042] The ratchet plane 1g and the unlocking groove 1h on the limiting ratchet 1f are 180 degrees apart in the circumferential direction.

[0043] A method for handling an underground accident of an oil and gas well, characterized in that when an underground accident occurs and a fish needs to be salvaged, the underground accident handling device of the oil and gas well is connected to the lowermost end of the drill string through an outer cylinder female buckle 1j and lowered into the well, and the drilling fluid is circulated when the fish is reached. The drilling fluid enters the annular cavity formed by the lower end face of the main body connecting plate 1c, the upper end face of the piston large diameter section 2a, the inner wall of the main body outer cylinder 1a and the outer wall of the main body inner cylinder 1b from the drilling fluid circulation hole 1i on the main body connecting plate 1c, and the drilling fluid pushes the driving piston 2 to move downward and compresses the reset spring 3 until the ring above the piston large diameter section 2a is The drilling fluid in the shaped cavity can flow into the inner tube 1b of the body through the drainage hole 1e, and the drilling fluid finally enters the outer annulus between the drill string and the well wall through the drilling fluid flow channel 9c; since the driving piston 2 is fixedly connected to the slip claw 8 by threads, the driving piston 2 drives the slip claw 8 to move downward during the downward movement; in the initial state, the inner diameter of the claw block 8a on the slip claw 8 is larger than the outer diameter of the small end of the guide head reducing section 9a and the outer diameter of the claw block 8a is smaller than the outer diameter of the guide head straight tube section 9b, and the outer diameter of the guide head straight tube section 9b is smaller than the inner diameter of the fish drop; when the slip claw 8 moves downward, the lower end of the claw block 8a slides along the guide head reducing section 9a so that The outer diameter of the claw block increases, and the cava teeth 8b bite the inner wall of the fish, and the pipe string is lifted. Under the friction between the cava teeth 8b and the inner wall of the fish, the cava claw 8 has a tendency to continue to slide downward relative to the guide head 9 and make the cava claw 8 bite the inner wall of the fish more and more tightly, so that the fish can be salvaged as the drill string is lifted. In this process, the ratchet 6 moves downward with the cava claw 8, and the engagement between the axial spline 1d and the spline groove 2c is released when the driving piston 2 moves downward to the limit position. Under the action of the torsion spring 5, the tip 6c of the ratchet is always in contact with the outer surface of the inner tube 1b of the body, and the tip 6c of the ratchet slides downward along the ratchet plane 1g. Restricted by the non-return step 1m, the tip 6c of the pawl can only slide downward but not upward; when the fish is stuck too tightly and cannot be extracted from the drill string, the processing device that holds the fish needs to be taken out. At this time, the drill string is rotated 180 degrees, the main body 1 rotates but the cava claw 8 holds the fish and cannot rotate, the pawl 6 slides in the annular groove of the limiting ratchet 1f until the unlocking groove 1h, and the drill string is vibrated slightly. Under the action of the reset spring 3, the piston 2 is driven to move upward and drive the pawl 6 to slide along the unlocking groove 1h, the outer diameter of the claw block 8a is reduced and the fish is released, and the drill string can be lifted up to lift the downhole accident processing device.

[0044] The specific implementation methods described above are used to illustrate the present invention rather than to limit the scope of the present invention. Any equivalent changes and modifications made by technicians in this field without departing from the concept and principle of the present invention are within the protection scope of the system of the present invention.

Claims

1. An oil and gas well downhole accident handling device, comprising a body (1), a driving piston (2), a return spring (3), a support ring plate (4), a torsion spring (5), a pawl (6), a pin (7), a slip claw (8) and a guide head (9), characterized in that The body (1) is provided with a body outer cylinder (1a), a body inner cylinder (1b) and a body connecting plate (1c); the upper end of the body outer cylinder (1a) is provided with an outer cylinder female buckle (1j); the body inner cylinder (1b) is provided with two axial splines (1d) evenly distributed along the circumferential direction, a drainage hole (1e), a limit ratchet (1f), an unlocking groove (1h) and an inner cylinder male buckle (1k); the body connecting plate (1c) is provided with a drilling fluid circulation hole (1i); the limit ratchet (1f) is provided with a ratchet plane (1g) and a non-return step (1m); the driving piston (2) comprises a piston large diameter section (2a) and a piston small diameter section (2b), the inner wall of the driving piston (2) is provided with two spline grooves (2c) evenly distributed along the circumferential direction, and the lower end of the piston small diameter section (2b) is provided with a piston male buckle (2d); the torsion spring (5) includes a torsion spring fixing section (5a) and a torsion spring loading section (5b); the pawl (6) includes a pawl rotating hole (6a), a pawl back side (6b) and a pawl tip (6c); the cava claw (8) includes a claw block (8a), an inter-block longitudinal groove (8c), a torsion spring placement groove (8d), a pin shaft mounting hole (8e) and a cava claw female buckle (8f), the outer wall of the claw block (8a) is provided with a cava tooth (8b), the claw block (8a) and The inter-block longitudinal grooves (8c) are evenly distributed in a staggered manner in the circumferential direction; the slip claw female buckle (8f) is arranged at the upper end of the inner wall of the slip claw (8); the inner wall of the torsion spring placement groove (8d) is provided with two torsion spring limit grooves (8g); the guide head (9) comprises a guide head reducing section (9a), a guide head straight section (9b), a drilling fluid channel (9c) and a guide head female buckle (9d); the driving piston (2) is sleeved in an annular space formed by the main body outer cylinder (1a) and the main body inner cylinder (1b); the axial spline (1d) cooperates with the spline groove (2c); the support ring plate (4) is connected to the lower end of the main body outer cylinder (1a) by a thread; the piston is large A return spring (3) is provided between the lower end surface of the diameter section (2a) and the support ring plate (4); the piston male buckle (2d) of the driving piston (2) cooperates with the crotch female buckle (8f) of the crotch claw (8); the inner cylinder male buckle (1k) cooperates with the guide head female buckle (9d); the torsion spring (5) is installed in the torsion spring placement groove (8d), the two ends of the torsion spring fixing section (5a) are arranged in the torsion spring limiting groove (8g), the torsion spring loading section (5b) applies pressure to the back side of the pawl (6b), the pin shaft (7) passes through the torsion spring (5), the pawl rotation hole (6a) and the pin shaft installation hole (8e), and the pawl (6) can rotate around the pin shaft (7);When an underground accident occurs and a fish needs to be salvaged, the oil and gas well underground accident handling device is connected to the lowermost end of the drill string through the outer cylinder female buckle (1j) and lowered into the well. When the fish is reached, the drilling fluid is circulated. The drilling fluid enters the annular cavity formed by the lower end surface of the main body connecting plate (1c), the upper end surface of the piston large diameter section (2a), the inner wall of the main body outer cylinder (1a) and the outer wall of the main body inner cylinder (1b) from the drilling fluid circulation hole (1i) on the main body connecting plate (1c). The drilling fluid pushes the driving piston (2) to move downward and compresses the reset spring (3) until the drilling fluid in the annular cavity above the piston large diameter section (2a) can flow into the main body through the drainage hole (1e). In the cylinder (1b), the drilling fluid finally enters the outer annulus between the drill string and the well wall through the drilling fluid flow channel (9c); since the driving piston (2) is fixedly connected to the slip claw (8) by means of a thread, the driving piston (2) drives the slip claw (8) to move downward during its downward movement; in the initial state, the inner diameter of the claw block (8a) on the slip claw (8) is larger than the outer diameter of the small end of the guide head reducing section (9a) and the outer diameter of the claw block (8a) is smaller than the outer diameter of the guide head straight tube section (9b), and the outer diameter of the guide head straight tube section (9b) is smaller than the inner diameter of the fish drop; when the slip claw (8) moves downward, the lower end of the claw block (8a) slides along the guide head reducing section (9a) so that the outer diameter of the claw block increases, and the slip tooth (8 b) bite the inner wall of the fish and lift the pipe column. Under the friction between the cava teeth (8b) and the inner wall of the fish, the cava claw (8) tends to continue to slide downward relative to the guide head (9) and makes the cava claw (8) bite the inner wall of the fish more and more tightly. The fish can be salvaged as the drill string is lifted. In this process, the ratchet claw (6) moves downward with the cava claw (8). The engagement between the axial spline (1d) and the spline groove (2c) is released when the driving piston (2) moves downward to the limit position. Under the action of the torsion spring (5), the tip of the ratchet claw (6c) is always in contact with the outer surface of the inner tube (1b) of the body. The tip of the ratchet claw (6c) slides downward along the ratchet tooth plane (1g) and is restrained by the reverse movement. The tip (6c) of the limiting pawl of the step (1m) can only slide downwards but not upwards; when the fish is stuck too tightly and cannot be extracted from the drill string, the processing device that holds the fish tightly needs to be taken out. At this time, the drill string is rotated 180 degrees, the body (1) rotates but the cava claw (8) holds the fish tightly and cannot rotate, the pawl (6) slides in the annular groove of the limiting ratchet (1f) until it reaches the unlocking groove (1h), the drill string is slightly vibrated, and under the action of the reset spring (3), the piston (2) is driven to move upwards and drive the pawl (6) to slide along the unlocking groove (1h), the outer diameter of the claw block (8a) is reduced and the fish is released, and the downhole accident processing device can be lifted up by lifting the drill string. ; 2. The downhole accident handling device for oil and gas wells according to claim 1 is characterized in that A plug (10) is threadedly connected in the pin shaft mounting hole (8e).

3. The downhole accident handling device for oil and gas wells according to claim 1 is characterized in that Sealing rings (11) are provided between the large diameter section (2a) of the piston and the inner wall of the outer cylinder (1a) of the main body, and between the supporting ring plate (4) and the outer wall of the upper end of the slip claw (8).

4. The downhole accident handling device for oil and gas wells according to claim 1 is characterized in that The outer diameter of the large end of the guide head reducing section (9a) is equal to the outer diameter of the guide head straight section (9b).

5. The downhole accident handling device for oil and gas wells according to claim 1 is characterized in that The ratchet plane (1g) and the unlocking groove (1h) on the limiting ratchet (1f) differ by 180 degrees in the circumferential direction.

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